Ultrasonic diagnostic equipment

ABSTRACT

An ultrasonic diagnostic equipment capable of reducing cost by reducing the number of transmission drive circuits for generating transmission pulse is disclosed. High voltage switches  3 - 1  to  3 - 32  for determining an aperture by selecting eight pieces from among transducer elements  2 - 1  to  2 - 32  to which transmission pulse is applied, and low voltage switches  11 - 1  to  11 - 16  for selecting 16 pieces from among the transducer elements  2 - 1  to  2 - 32  to receive ultrasonic echo are provided individually. Regarding the high voltage switches  3  for transmission, four inputs are integrated into one, and a distribution circuit of  1:4  is constructed. Regarding the low voltage switches  11  for reception, two outputs are integrated into one, and a multiplexer of  2:1  is constructed. Linear scanning is performed by only eight pulsers (transmission drive circuits)  4 - 1  to  4 - 8 . The high voltage switches  3  for transmitting ultrasonic waves and the low voltage switches  11  for receiving ultrasonic waves are separated from each other. Therefore, the number of the pulsers (transmission drive circuits)  4  can be reduced, and cost for circuits can be reduced while performance is maintained.

TECHNICAL FIELD

The present invention relates to an ultrasonic diagnostic equipment, andmore particularly to an ultrasonic diagnostic equipment for performinglinear scanning by using arrayed transducer elements.

BACKGROUND ART

An ultrasonic diagnostic equipment is an equipment for observing aninternal state of an examination object by transmitting an ultrasonicwave from an ultrasonic probe (probe) arraying ultrasonic transducerelements into the examination object, receiving at the ultrasonic probethe ultrasonic wave returned after being reflected inside theexamination object, and signal-processing and imaging the receivedultrasonic wave. As an ultrasonic beam control method in the ultrasonicdiagnostic equipment, there are sector scanning method and linearscanning method. The sector scanning method is a scanning method,wherein a measurement cross sectional layer is expressed as polarcoordinates, a wave transmitting position of an ultrasonic wave is setto an origin, a traveling direction of the ultrasonic wave is designatedas a diameter direction, and a wave transmitting direction is designatedas an angle direction. The linear scanning method is a scanning method,wherein a measurement cross sectional layer is expressed as Cartesiancoordinates, a traveling direction of an ultrasonic wave is designatedas one axis, and a wave transmitting position of the ultrasonic wave ismoved on the other orthogonal axis.

In an ultrasonic diagnostic equipment for performing the linear scanningby using arrayed transducer elements of an ultrasonic probe, focusingtechnique, in which convergence of ultrasonic beam is performed by usingthe plurality of arrayed transducer elements concurrently is utilized.There is transmission focusing technique, wherein control is made sothat ultrasonic beam is converged at a certain test part in the body byshifting generation start timing of pulse given to respective transducerelements of an ultrasonic probe. Further, there is an ultrasonicdiagnostic equipment for performing synthetic aperture scanning.

Descriptions will be hereinafter given of the focusing techniquebriefly. A transmission timing signal is output from a transmissiontiming control circuit to a driver at a timing that ultrasonic beamconcurrently reaches the part where the ultrasonic beam is desired to beconverged. The driver generates ultrasonic transmission pulse accordingto the transmission timing signal, and transmits the ultrasonictransmission pulse to a transducer element. Each driver and eachtransducer element are connected one for one. A signal converted to anultrasonic wave at the transducer element is reflected inside theexamination object, converted to an electrical signal at the transducerelement, and delay-added at a reception beam forming device.

In the synthetic aperture scanning, drive pulse is generated in atransmission circuit, and a selected transducer element is driven. Thetransducer element generates ultrasonic pulse, and ultrasonic pulsereflected inside the examination object is received at the transducerelement as an echo ultrasonic wave. The receiver signal is amplified,converted to digital data, and written in a memory. After writing in thememory is finished, a different transducer element is selected, and areceiver signal is written in the memory as above. The respectivereceiver signals stored in the memory are added with a given timedifference. The added receiver signals are signal-processed at a signalprocessor, and shown on a display part. When the examination objectremains stationary during reception, a signal from a specific inner partof the examination object can be emphasized, and sharp receptiondirectivity can be obtained. Some examples of conventional ultrasonicdiagnostic equipments will be hereinafter cited. “Ultrasonic diagnosticequipment” disclosed in Japanese Unexamined Patent ApplicationPublication No. H07-67879 is an ultrasonic diagnostic equipment forperforming the synthetic aperture, wherein image deterioration caused bymotion of an examination object is prevented. Arrayed transducerelements are driven by a transmission circuit, and ultrasonic waves aretransmitted into an examination object. Among echo received at thetransducer elements, a signal of a given transducer element is selectedby a switch. The signal is appropriately amplified at an amplifier,converted to a digital signal at an A/D converter, and then delay-addedat a beam synthetic part, and stored in a memory. As above, anultrasonic wave is transmitted again, and a signal of other transducerelement is selected by a switch. Similar signal processing is performedat the amplifier, the A/D converter, and the beam synthetic part, andthen the signal is added to the delay-added signal which has been storedin the memory. These added signals are provided with signal processingat a signal processing part, and then shown on a display part.

“Ultrasonic diagnostic equipment” disclosed in Japanese UnexaminedPatent Application Publication No. 2000-152937 is an ultrasonicdiagnostic equipment, wherein the number of transmission drivers isreduced without losing a shape of reception beam. By inserting a switch(diode) between the transmission driver and a transducer element, aplurality of transducer elements can be driven by one driver. Inreception, signals of the respective transducer elements can beprocessed independently.

A concrete example of the conventional ultrasonic diagnostic equipmentwhich performs the linear scanning will be hereinafter described withreference to FIG. 13. FIG. 13 is a block diagram of a front end part ofthe ultrasonic diagnostic equipment. In FIG. 13, a probe 1 is anultrasonic probe comprising an array of transducer elements 2-1 to 2-32.The transducer elements 2-1 to 2-32 are actuators/sensors fortransmitting and receiving ultrasonic waves. High voltage switches 3-1to 3-32 are switches for selecting transducer elements corresponding toan aperture to be used, and applying high voltage transmission pulse.Pulsers 4-1 to 4-16 are transmission drive circuits generatingtransmission pulse. A trigger generator 5 is a means for generatingtransmission trigger signals. Limiters 6-1 to 6-16 are means forclipping the high voltage transmission pulse to protect subsequent stagecircuits. A cross point switch (CPS) 7 is a means for sorting and addinglimiter outputs. A/D converters 8-1 to 8-8 are means for convertinganalog receiver signals to digital signals. A beam forming device 9 is ameans for delay-adding the digital converted data. A controller 10 is ameans for performing timing control of a transmission circuit and areception circuit.

Operation of the conventional ultrasonic diagnostic equipmentconstructed as above will be hereinafter described. The triggergenerator 5 generates a transmission trigger signal, a timing signal foroutputting ultrasonic pulse. According to the transmission triggersignal, the pulsers 4-1 to 4-16 generate transmission pulse. In order toprotect circuits such as the subsequent stage cross point switch fromhigh voltage transmission pulse generated at the pulsers 4-1 to 4-16,the limiters 6-1 to 6-16 clip the high voltage transmission pulse toenter the cross point switch 7. By selectively turning ON/OFF the highvoltage switches 3-1 to 3-32, the high voltage transmission pulse isapplied to only transducer elements to be driven. By this selectiveoperation, a position and a width of an aperture of the probe 1 aredetermined.. Selected 16 transducer elements of the probe 1 transmitultrasonic waves to the examination object.

Reflected ultrasonic waves from the examination object are received atthe transducer elements 2-1 to 2-32. The receiver signals pass selected16 high voltage switches, enter the cross point switch 7 via thelimiters 6-1 to 6-16. At the cross point switch 7, the receiver signalsare sorted and added, and then changed into eight synthetic receiversignals. The synthetic receiver signals are converted to digital signalsat the A/D converters 8-1 to 8-8. The digital converted receiver signalsare delay-added and directivity is adjusted at the beam forming device9. The resultant output signal is converted to an image signal at anunshown circuit, and displayed. The controller 10 performs timingcontrol of the transmission circuit and the reception circuit of theultrasonic waves.

In the foregoing conventional ultrasonic diagnostic devices, however,many circuits are required, and therefore, there is a problem thatmanufacturing the conventional ultrasonic diagnostic device is costly.In particular, there is a problem that manufacturing the transmissiondrive circuit (pulser) for generating transmission pulse issignificantly costly.

DISCLOSURE OF THE INVENTION

It is an object of the invention to provide an ultrasonic diagnosticequipment, which can solve the foregoing conventional problems andperform linear scanning with few transmission drive circuits.

In order to solve the foregoing tasks, in the invention, the ultrasonicdiagnostic equipment is an ultrasonic diagnostic equipment comprising; aplurality of arrayed ultrasonic transducer elements, a plurality oftransmission drive circuits for driving the ultrasonic transducerelements, a plurality of high voltage switches for connecting theultrasonic transducer elements and the transmission drive circuits, aplurality of limiters for clipping transmission pulse having a givenvoltage or more, which is generated at the transmission drive circuits,a cross point switch which has input terminals whose number is largerthan of the transmission drive circuits, and performs sorting and addingsignals received at the ultrasonic transducer elements, low voltageswitches for connecting output signals of the limiters to the inputterminals of the cross point switch, A/D converters for convertingoutput signals of the cross point switch to digital signals, and a beamforming device for delay-adding the output signals of the A/Dconverters, wherein:

-   -   an ultrasonic pulse transmission circuit has fewer channels than        a reception circuit. Since the ultrasonic diagnostic equipment        is constructed as above, connection patterns of the high voltage        switch for transmission and connection patterns of the low        voltage switches for reception can be changed independently, and        linear scanning with sufficient precision can be performed even        with few transmission drive circuits.

Further, the ultrasonic diagnostic equipment comprises a means forchanging connection patterns of the high voltage switches, and a meansfor turning ON/OFF the high voltage switches by a connection patternwith which an aperture wider than a minimum aperture determined by thenumber of the transmission drive circuits is obtained. Since theultrasonic diagnostic equipment is constructed as above, an aperturewider than a minimum aperture determined by the number of thetransmission drive circuits can be obtained by changing connectionmethods of the high voltage switches for transmission. In particular,when focus is set at the deep part, a beam shape can be improved.

Further, the ultrasonic diagnostic equipment comprises a means foridentifying a type of a probe connected, and a means for changing a sizeof the aperture according to the type of the probe. Since the ultrasonicdiagnostic equipment is constructed as above, an optimum aperturediameter corresponding to a prove can be obtained by changing connectionmethods of the high voltage switches for transmission according to probetypes, and a beam shape can be improved.

Further, the ultrasonic diagnostic equipment comprises a means forinputting a displayed depth, and a means for changing a size of theaperture according to the input displayed depth. Since the ultrasonicdiagnostic equipment is constructed as above, an optimal aperturediameter corresponding to a prove can be obtained by changing connectionmethods of the high voltage switches for transmission according todisplayed depths, and a beam shape can be improved.

Further, the ultrasonic diagnostic equipment comprises a means forinputting a display mode, and a means for changing a size of theaperture according to the input display mode. Since the ultrasonicdiagnostic equipment is constructed as above, an optimal aperturediameter corresponding to a prove can be obtained by changing connectionmethods of the high voltage switches for transmission according todisplay modes, and a beam shape can be improved.

Further, the ultrasonic diagnostic equipment comprises a means forinputting a transmission focus depth, and a means for changing a size ofthe aperture according to the input transmission focus depth. Since theultrasonic diagnostic equipment is constructed as above, an optimalaperture diameter corresponding to a prove can be obtained by changingconnection methods of the high voltage switches for transmissionaccording to transmission focus depths, and a beam shape can beimproved.

Further, the ultrasonic diagnostic equipment comprises a means forinputting a center frequency of transmission pulse, and a means forchanging a size of the aperture according to the input center frequency.Since the ultrasonic diagnostic equipment is constructed as above, anoptimal aperture diameter corresponding to a prove can be obtained bychanging connection methods of the high voltage switches fortransmission according to center frequencies of transmission pulse, anda beam shape can be improved.

Further, the ultrasonic diagnostic equipment comprises a means forselecting whether a higher resolution is prioritized or whether a widerdynamic range is prioritized, and a means for selecting transducerelements to be used according to characteristics to be prioritized.Since the ultrasonic diagnostic equipment is constructed as above, oneof resolution improvement and side lobes reduction can be selected byselecting whether transducer elements not used are gathered in thevicinity of center or gathered at end parts when an aperture diameter iswidened larger than a minimum aperture determined by the number of thetransmission drive circuits. Therefore, an image capable of being easilydiagnosed can be displayed.

Further, in the ultrasonic diagnostic equipment, a memory for storingdata for one sound ray, and an adder for adding an output of the memoryand an output of the beam forming device are provided on the output sideof the beam forming device. Since the ultrasonic diagnostic equipment isconstructed as above, an optimal beam shape can be realized byperforming aperture synthesis by driving transducer elements separatedin two groups.

Further, in the ultrasonic diagnostic equipment, high voltage switchesfor connecting two adjacent transducer elements are provided. Since theultrasonic diagnostic equipment is constructed as above, transducerelements whose number is at maximum twice of the number of transmissiondrive circuits can be concurrently driven. In particular, when focus isset at a deep part, a beam shape can be improved, and a high imagequality can be obtained.

Further, in the ultrasonic diagnostic equipment, diodes are insertedbetween the high voltage switches and the transducer elements. Since theultrasonic diagnostic equipment is constructed as above, receptionchannels can be separated, and an optimum beam shape can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a first embodiment of the invention;

FIG. 2 is an explanation drawing showing a connection of high voltageswitches of an ultrasonic diagnostic equipment in a second embodiment ofthe invention;

FIG. 3 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a third embodiment of the invention;

FIG. 4 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a fourth embodiment of the invention;

FIG. 5 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a fifth embodiment of the invention;

FIG. 6 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a sixth embodiment of the invention;

FIG. 7 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a seventh embodiment of the invention;

FIG. 8 is an explanation drawing showing a connection of high voltageswitches of an ultrasonic diagnostic equipment in an eighth embodimentof the invention;

FIG. 9 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a ninth embodiment of the invention;

FIG. 10 is an explanation drawing showing a connection of high voltageswitches of the ultrasonic diagnostic equipment in the ninth embodimentof the invention;

FIG. 11 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in a tenth embodiment of the invention;

FIG. 12 is a block diagram of a front end part of an ultrasonicdiagnostic equipment in an eleventh embodiment of the invention; and

FIG. 13 is a block diagram of a front end part of a conventionalultrasonic diagnostic equipment.

BEST MODE FOR CARRYING OUT THE INVENTION

Detailed descriptions will be hereinafter given of ultrasonic diagnosticequipments of embodiments of the invention with reference to FIGS. 1 to12.

FIRST EMBODIMENT

A first embodiment of the invention is an ultrasonic diagnosticequipment, wherein switches for selecting transducer elements totransmit ultrasonic waves are separated from switches for selectingtransducer elements to receive the ultrasonic waves.

FIG. 1 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the first embodiment of theinvention. In FIG. 1, a probe 1 is an ultrasonic probe comprising anarray of transducer elements 2-1 to 2-32. The transducer elements 2-1 to2-32 are actuators/sensors for transmitting and receiving ultrasonicwaves. High voltage switches (HV-SW) 3-1 to 3-32 are switches forselecting transducer elements corresponding to an aperture to be usedand applying high voltage transmission pulse. Pulsers 4-1 to 4-16 aretransmission drive circuits for generating the high voltage transmissionpulse. A trigger generator 5 is a means for generating a transmissiontrigger signal, a timing signal to output ultrasonic pulse. Limiters 6-1to 6-32 are means for clipping (limit a voltage value) the high voltagetransmission pulse to enter a cross point switch 7 in order to protectcircuits such as the subsequent stage cross point switch 7 from the highvoltage transmission pulse generated in the pulsers 4-1 to 4-8. Thecross point switch 7 is a means for sorting and adding output signals ofthe limiters 6-1 to 6-32 to obtain synthetic receiver signals. A/Dconverters 8-1 to 8-8 are means for converting the analog syntheticreceiver signals to digital signals. A beam forming device 9 is a meansfor delay-adding the digital converted synthetic receiver signals andadjusting directivity. A controller 10 is a means for performing timingcontrol of a transmission circuit and a reception circuit of ultrasonicwaves. Low voltage switches (LV-SW) 11-1 to 11-16 are switches forselecting receiver signals to be used from among the output signals ofthe limiters 6-1 to 6-32.

Operation of the ultrasonic diagnostic equipment in the first embodimentof the invention constructed as above will be hereinafter described. Itis different from conventional equipments that the high voltage switches3-1 to 3-32 for selecting transducer elements to transmit ultrasonicpulse are separated from the low voltage switches 11-1 to 11-16 forselecting transducer elements which has received ultrasonic echo. In thecircuit for transmitting ultrasonic pulse, inputs into given four of thehigh voltage switches 3-1 to 3-32 are conducted by a given one of thepulsers 4-1 to 4-8, and a distribution circuit of 1:4 is constructed.Therefore, when the ultrasonic pulse is transmitted, 32 pieces of thetransducer elements 2-1 to 2-32 can be driven by the eight pulsers, andtherefore, linear scanning is enabled. In the circuit for receivingultrasonic echo, every two outputs of the low voltage switches 11-1 to11-16 are integrated into one respectively, and a multiplexer of 2:1 isconstructed.

It is impossible to adopt dynamic focus as in the case of reception, asa method for adjusting focus in transmitting ultrasonic pulse.Therefore, there are few cases that beam control to focus ultrasonicwaves on a point at a target depth by using many channels of transducerelements. Therefore, the transmission circuit of ultrasonic pulse canhave few channels than of the reception circuit.

The trigger generator 5 generates a transmission trigger signal, atiming signal to output ultrasonic pulse. According to the transmissiontrigger signal, the pulsers 4-1 to 4-8 generate transmission pulse. Byselectively turning ON eight of the high voltage switches 3-1 to 3-32,high voltage transmission pulse is applied to only transducer elementsto be driven among the transducer elements 2-1 to 2-32 arrayed in theprobe 1. By this selective operation, a position and a width of anaperture of the probe 1 are determined. The selected eight transducerelements of the probe 1 transmit ultrasonic waves to an examinationobject. In order to protect circuits such as the subsequent stage crosspoint switch from the high voltage transmission pulse applied to thetransducer elements, the limiters 6-1 to 6-32 clips the high voltagetransmission pulse to enter the cross point switch 7.

Reflected ultrasonic waves from the examination object are received atthe transducer elements 2-1 to 2-32. The receiver signals pass 16 piecesselected from among the low voltage switches 11-1 to 11-32, and enterthe cross point switch 7. At the cross point switch 7, the receiversignals are sorted and added, and then changed into eight syntheticreceiver signals. At the A/D converters 8-1 to 8-8, the syntheticreceiver signals are converted to digital signals. At the beam formingdevice 9, the digital converted receiver signals are delay-added, anddirectivity is adjusted. The resultant output signal is converted to animage signal in an unshown circuit, and displayed. The controller 10performs timing control of the transmission circuit and the receptioncircuit of the ultrasonic waves.

As mentioned above, in the first embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein the switches3-1 to 3-32 for selecting transducer elements to transmit ultrasonicwaves are separated from the switches 11-1 to 11-32 for selecting thevibratos 2-1 to 2-32 to receive the ultrasonic waves. Therefore, thenumber of the transmission drive circuits (pursers) can -be reduced, andmanufacturing cost can be reduced while performance is maintained.

SECOND EMBODIMENT

An ultrasonic diagnostic equipment of a second embodiment of theinvention will be hereinafter described by using FIGS. 1 and 2. Theultrasonic diagnostic equipment of the second embodiment of theinvention is an ultrasonic diagnostic equipment, wherein a connectionpattern of high voltage switches for selecting transducer elements totransmit ultrasonic waves is changed at the controller 10 into aconnection pattern wherein an aperture wider than a minimum aperturedetermined by the number of transmission drive circuits can be obtained,and the high voltage switches are turned ON/OFF at the controller 10.

FIG. 2 is an explanation drawing of a connection method of the highvoltage switches of a transmission circuit of the ultrasonic diagnosticequipment in the second embodiment of the invention. The transducerelements 2-1 to 2-32 are actuators/sensors for transmitting or receivingultrasonic waves. The high voltage switches (HV-SW) 3-1 to 3-32 areswitches for selecting transducer elements corresponding to an apertureto be used and applying high voltage transmission pulse. A generalconstruction of the ultrasonic diagnostic equipment in the secondembodiment is similar to of the ultrasonic diagnostic equipment in thefirst embodiment shown in FIG. 1.

Operation of the ultrasonic diagnostic equipment in the secondembodiment of the invention constructed above will be hereinafterdescribed. By changing ON/OFF patterns of the high voltage switches, anaperture wider than a minimum aperture determined by the number of thetransmission drive circuits (8) (8 in units of array pitch of thetransducer elements) is realized. Pattern P1 is a regular switchconnection pattern. ● mark indicates a position of a switch to be turnedON. An aperture is a minimum aperture (8), which is determined by thenumber of the transmission drive circuits (8). In PA1 of Pattern P1, acenter of the aperture becomes Aperture position #1. In PA2 of PatternP1, a center of the aperture becomes Aperture position #2. In PA3 ofPattern P1, a center of the aperture becomes Aperture position #3. InPA4 of Pattern P1, a center of the aperture becomes Aperture position#4.

In Pattern P2, a width of an aperture becomes 12. In PB1 of Pattern 2, acenter of the aperture becomes Aperture position #1. In PB2 of Pattern2, a center of the aperture becomes Aperture position #2. In PB3 ofPattern 2, a center of the aperture becomes Aperture position #3. In PB4of Pattern 2, a center of the aperture becomes Aperture position #4. InPattern P3, a width of an aperture becomes 16. In PC1 of Pattern 3, acenter of the aperture becomes Aperture position #1. In PC2 of Pattern3, a center of the aperture becomes Aperture position #2. In PC3 ofPattern 3, a center of the aperture becomes Aperture position #3. In PC4of Pattern 3, a center of the aperture becomes Aperture position #4.

As above, by changing positions of ON connection of the high voltageswitches for selecting transducer elements to transmit ultrasonic waves,an aperture wider than the minimum aperture (8) determined by the numberof the transmission drive circuits (8) can be realized. When a wideraperture is required since, for example, a channel pitch of thetransducer elements of the probe 1 is narrow, the aperture can be easilywidened.

As mentioned above, in the second embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein theconnection pattern of the high voltage switches is changed, and the highvoltage switches are turned ON/OFF by the connection pattern wherein anaperture becomes wider than the minimum aperture determined by thenumber of the transmission drive circuits. Therefore,.the number of thetransmission drive circuits (pulsers) can be reduced, and an inexpensiveultrasonic diagnostic equipment can be realized while performance ismaintained.

THIRD EMBODIMENT

A third embodiment of the invention is an ultrasonic diagnosticequipment, wherein an ID generator is provided in a probe, and an IDencoder is provided in an equipment body.

FIG. 3 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the third embodiment of theinvention. In FIG. 3, an ID generator 12 is a means for generating anidentification code representing a probe type. An ID encoder 13 is ameans for converting the identification code to a control signal. Ageneral construction of the ultrasonic diagnostic equipment in the thirdembodiment is similar to of the ultrasonic diagnostic equipment in thefirst embodiment shown in FIG. 1, except that the ID generator 12 isprovided in the probe 1 and the ID encoder 13 is provided in theequipment body.

Operation of the ultrasonic diagnostic equipment in the third embodimentof the invention constructed as above will be hereinafter described.When the probe 1 is connected to the equipment body, the ID generator 12generates an identification code representing a probe type, andtransmits the generated identification code to the ID encoder 13provided in the equipment body. The ID encoder 13 converts theidentification code to a control signal, and outputs the control signalto the controller 10. As above, the probe type is read by the controller10 by using the ID generator 12 and the ID encoder 13. The controller 10controls an aperture diameter of ultrasonic beam by changing patterns ofON connection of the high voltage switches 3-1 to 3-32 according toprobe types.

As described above, in the third embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein the IDgenerator is provided in the probe and the ID encoder is provided in theequipment body. Therefore, an optimum aperture diameter can be realizedfor each probe, a transmission circuit amount can be reduced, and aninexpensive ultrasonic diagnostic equipment can be realized whileperformance is maintained.

FOURTH EMBODIMENT

A fourth embodiment of the invention is an ultrasonic diagnosticequipment, wherein a displayed depth input equipment is added.

FIG. 4 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the forth embodiment of theinvention. In FIG. 4, a displayed depth input equipment 14 is a meansfor inputting data which indicates a target displayed depth. A generalconstruction of the ultrasonic diagnostic equipment in the forthembodiment is similar to of the ultrasonic diagnostic equipment in thefirst embodiment shown in FIG. 1, except that the displayed depth inputequipment 14 is added.

Operation of the ultrasonic diagnostic equipment in the forth embodimentof the invention constructed as above will be hereinafter described. Thedisplayed depth input equipment 14 provides the controller 10 withdisplayed depth information. The controller 10 controls an aperturediameter of ultrasonic beam by changing patterns of ON connection of thehigh voltage switches 3-1 to 3-32 according to displayed depths. When adeep part is displayed, the pattern of ON connection of the high voltageswitches 3-1 to 3-32 is changed so that the aperture diameter ofultrasonic beam can be widened. When a shallow part is displayed, thepattern of ON connection of the high voltage switches 3-1 to 3-32 ischanged so that the aperture diameter of ultrasonic beam can benarrowed.

As mentioned above, in the fourth embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein thedisplayed depth input equipment is added. Therefore, an optimum aperturediameter can be realized for each displayed depth, a transmissioncircuit amount can be reduced, and an inexpensive ultrasonic diagnosticequipment can be realized while performance is maintained.

FIFTH EMBODIMENT

A fifth embodiment of the invention is an ultrasonic diagnosticequipment, wherein a display mode input equipment is added.

FIG. 5 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the fifth embodiment of theinvention. In FIG. 5, a display mode input equipment 15 is a means forinputting data which indicates a target display mode. A generalconstruction of the ultrasonic diagnostic equipment in the fifthembodiment is similar to of the ultrasonic diagnostic equipment in thefirst embodiment shown in FIG. 1, except that the display mode inputequipment 15 is added.

Operation of the ultrasonic diagnostic equipment in the fifth embodimentof the invention constructed as above will be hereinafter described. Inthe ultrasonic diagnostic equipment, there are various signalprocessing/display modes such as B mode, color Doppler mode, and pulseDoppler mode. Optimal aperture diameters vary according to therespective modes. The display mode input equipment 15 provides thecontroller 10 with display mode information. The controller 10 controlsaperture diameters of ultrasonic beam by changing patterns of ONconnection of the high voltage switches 3-1 to 3-32 according to displaymodes.

The B mode is a mode, wherein a pulse transmission position or a pulsetransmission direction is moved linearly, and a tomogram of a target inwhich an envelope curve wave form of an echo receiver signal isintensity-modulated is displayed. When the B mode is used for display, apattern of ON connection of the high voltage switches 3-1 to 3-32 ischanged so that an aperture diameter of ultrasonic beam can be widened.

The color Doppler mode is a mode, wherein a flow rate (average Dopplerdeflection frequency) in each channel measured on ultrasonic beam isquantized into about eight levels, a flow coming close to the prove isconverted to red color luminance information, a flow getting away fromthe probe is converted to blue color luminance information, and theconverted information is shown on a display, while a measurement beamdirection is sequentially scanned in color Doppler method whichvisualizes a flow rate distribution in a two-dimensional fault plane.When the color Doppler mode is used for display, a pattern of ONconnection of the high voltage switches 3-1 to 3-32 is changed so thatan aperture diameter of ultrasonic beam can be narrowed.

The pulse Doppler mode is a mode for identifying and displaying areflection part by pulsing transmitted ultrasonic wave by Dopplermethod. When the pulse Doppler mode is used for display, a pattern of ONconnection of the high voltage switches 3-1 to 3-32 is changed so thatan aperture diameter of ultrasonic beam can be narrowed.

As mentioned above, in the fifth embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein the displaymode input equipment is added. Therefore, an optimal aperture diametercan be realized for each display mode, a transmission circuit amount canbe reduced, and an inexpensive ultrasonic diagnostic equipment can berealized while performance is maintained.

SIXTH EMBODIMENT

A sixth embodiment of the invention is an ultrasonic diagnosticequipment, wherein a transmission focus depth input equipment is added.

FIG. 6 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the sixth embodiment of theinvention. In FIG. 6, a transmission focus depth input equipment 16 is ameans for inputting data which indicates a target transmission focusdepth. A general construction of the ultrasonic diagnostic equipment inthe sixth embodiment is similar to of the ultrasonic diagnosticequipment in the first embodiment shown in FIG. 1, except that thetransmission focus depth input equipment 16 is added.

Operation of the ultrasonic diagnostic equipment in the sixth embodimentof the invention constructed above will be hereinafter described. In theultrasonic diagnostic equipment, a transmission focus position can bechanged even though in the case of the same displayed depth. Optimumaperture diameters vary according to focus depths. The transmissionfocus depth input equipment 16 inputs data which indicates a targettransmission focus depth to the controller 10. The controller 10controls aperture diameters of ultrasonic beam by changing patterns ofON connection of the high voltage switches 3-1 to 3-32 according totransmission focus depths.

When a deep transmission focus depth is to be obtained, a pattern of ONconnection of the high voltage switches 3-1 to 3-32 is changed so thatan aperture diameter of ultrasonic beam can be widened. When a shallowtransmission focus depth is to be obtained, a pattern of ON connectionof the high voltage switches 3-1 to 3-32 is changed so that an aperturediameter of ultrasonic beam can be narrowed.

As mentioned above, in the sixth embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein the focusdepth input equipment is added. Therefore, an optimal aperture diametercan be realized for each transmission focus depth, a transmissioncircuit amount can be reduced, and an inexpensive ultrasonic diagnosticequipment can be realized while performance is maintained.

SEVENTH EMBODIMENT

A seventh embodiment of the invention is an ultrasonic diagnosticequipment, wherein a center frequency input equipment is added.

FIG. 7 is a block diagram of a transmission/reception circuit in theseventh embodiment of the invention. In FIG. 7, a center frequency inputequipment 17 is a means for inputting data which indicates a centerfrequency of transmission pulse. A general construction of theultrasonic diagnostic equipment in the seventh embodiment is similar toof the ultrasonic diagnostic equipment in the first embodiment shown inFIG. 1, except that the center frequency input equipment 17 is added.

Operation of the ultrasonic diagnostic equipment in the seventhembodiment of the invention constructed above will be hereinafterdescribed. In the ultrasonic diagnostic equipment, center frequencysettings of transmission pulse are changed according to examined partseven the same probe is used. Optimum aperture diameters vary accordingto center frequencies. The center frequency input equipment 17 inputsdata which indicates a center frequency of transmission pulse to thecontroller 10. The controller 10 controls aperture diameters ofultrasonic beam by changing patterns of ON connection of the highvoltage switches 3-1 to 3-32 according to center frequencies oftransmission pulse.

When a low center frequency of transmission pulse is to be obtained, apattern of ON connection of the high voltage switches 3-1 to 3-32 ischanged so that an aperture diameter of ultrasonic beam can be widened.When a high center frequency of transmission pulse is to be obtained, apattern of ON connection of the high voltage switches 3-1 to 3-32 ischanged so that an aperture diameter of ultrasonic beam can be narrowed.

As mentioned above, in the seventh embodiment of the invention, theultrasonic -diagnostic equipment has a construction, wherein the centerfrequency input equipment is added. Therefore, an optimal aperturediameter can be realized for each center frequency, a transmissioncircuit amount can be reduced, and an inexpensive ultrasonic diagnosticequipment can be realized while performance is maintained.

EIGHTH EMBODIMENT

An eighth embodiment of the invention is an ultrasonic diagnosticequipment, wherein whether a higher resolution is prioritized or whethera wider dynamic range is prioritized is selected, and transducerelements to be used are selected according to characteristics to beprioritized.

FIG. 8 is an explanation drawing of a connection method of high voltageswitches of a transmission circuit of the ultrasonic diagnosticequipment in the eighth embodiment of the invention. In FIG. 8, thetransducer elements 2-1 to 2-32 are actuators/sensors for transmittingor receiving ultrasonic wave. The high voltage switches (HV-SW) 3-1 to3-32 are switches for selecting transducer elements corresponding to anaperture to be used and applying high voltage transmission pulse. Ageneral construction of the ultrasonic diagnostic equipment in theeighth embodiment is similar to of the ultrasonic diagnostic equipmentof the first embodiment shown in FIG. 1.

Operation of the ultrasonic diagnostic equipment in the eighthembodiment of the invention constructed above will be hereinafterdescribed. By changing patterns of ON connection of the high voltageswitches 3-1 to 3-32, a beam shape is changed even though in the case ofthe same aperture diameter. In Pattern P2, transducer elements to beused are placed relatively at the center of the aperture. In Pattern P4,transducer elements to be used are distributed relatively at ends of theaperture. In Pattern P2, a beam shape with few side lobes can beobtained. In Pattern P4, a beam shape with a thin main lobe can beobtained. One of these patterns is selected by changing an unshownswitch by an operator.

In Pattern P2, a width of the aperture is 12 pieces when expressing thewidth by the number of transducer elements to be used, the beam shapewith few side lobes can be obtained, and its dynamic range is widened.In PB1 of Pattern P2, a center of the aperture becomes Aperture position#1. In PB2 of Pattern P2, a center of the aperture becomes Apertureposition #2. In PB3 of Pattern P2, a center of the aperture becomesAperture position #3. In PB4 of Pattern P2, a center of the aperturebecomes Aperture position #4.

In Pattern P4, a width of an aperture becomes 12 as well. However, thebeam shape with a thin main lobe is obtained, and a resolution becomesimproved. In PD1 of Pattern 4, a center of the aperture becomes Apertureposition #1. In PD2 of Pattern 4, a center of the aperture becomesAperture position #2. In PD3 of Pattern 4, a center of the aperturebecomes Aperture position #3. In PD4 of Pattern 4, a center of theaperture becomes Aperture position #4.

As mentioned above, in the eighth embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein whether ahigher resolution is prioritized or whether a wider dynamic range isprioritized is selected, and transducer elements to be used are selectedaccording to characteristics to be prioritized. Therefore, the number ofthe transmission drive circuits (pulsers) can be reduced, and aninexpensive ultrasonic diagnostic equipment can be realized whileperformance is maintained.

NINTH EMBODIMENT

A ninth embodiment of the invention is an ultrasonic diagnosticequipment, wherein a memory 18 and an adder 19 are added on the outputside of a beam forming device.

FIG. 9 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the ninth embodiment of theinvention. In FIG. 9, the memory 18 is a memory for storing the firstreceiver signal. The adder 19 is a means for adding the first and thesecond receiver signals. A general construction of the ultrasonicdiagnostic equipment in the ninth embodiment is similar to of theultrasonic diagnostic equipment in the first embodiment shown in FIG. 1,except that the memory 18 and the adder 19 are added on the output sideof the beam forming device. FIG. 10 is an operational explanationdrawing of the ultrasonic diagnostic equipment in the ninth embodiment.

Operation of the ultrasonic diagnostic equipment in the ninth embodimentof the invention constructed above will be hereinafter described. Anaperture using 16 transducer elements among 32 transducer elements ofthe probe 1 is set as Apertures K1 to K4 in FIG. 10. The aperture isdivided into two portions, and transmission and reception of ultrasonicwave is performed two times respectively. In the first time, as shown as1A of Aperture K1 in FIG. 10, ultrasonic wave is transmitted by usingeight vibratos at the central part of the aperture. In the second time,as shown as 1B of Aperture K1 in FIG. 10, transmission is performed byusing eight transducer elements at the both ends of the aperture.Receiver signal of the first time is stored in the memory 18. Thereceiver signal of the first time is outputted from the memory 18,correspondingly to a timing when a receiver signal of the second time isoutput from the beam forming device. These two signals are added at theadder 19. A center of Aperture K1 having an aperture width 16 pcs (inexpressing by the number of the transducer elements to be used) becomesAperture position K1. Regarding Aperture K2, a width is 16 and a centerbecomes Aperture position K2 Regarding Aperture K3, a width is 16 and acenter becomes Aperture position K3. Regarding Aperture K4, a width ofthe aperture is 16 pcs (in expressing by the number of transducerelements to be used) and a center becomes Aperture position K4. Byperforming aperture synthesis as above, performing transmission andreception one time can provide effects similar to in performingtransmission and reception with an aperture by twice of the number ofchannels of the transmission drive circuits.

As mentioned above, in the ninth embodiment of the invention, theultrasonic diagnostic equipment has a construction, wherein the memoryand the adder are added on the output side of the beam forming device.Therefore, a transmission circuit amount can be reduced, and aninexpensive ultrasonic diagnostic equipment can be realized whileperformance is maintained.

TENTH EMBODIMENT

A tenth embodiment of the invention is an ultrasonic diagnosticequipment, wherein high voltage switches for connecting adjacenttransducer elements are added.

FIG. 11 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the tenth embodiment of theinvention. In FIG. 11, high voltage switches 20-1 to 20-16 are switchesfor connecting adjacent transducer elements. A general construction ofthe ultrasonic diagnostic equipment in the tenth embodiment is similarto of the ultrasonic diagnostic equipment in the first embodiment shownin FIG. 1, except that the high voltage switches 20-1 to 20-16 forconnecting adjacent transducer elements are added.

Operation of the ultrasonic diagnostic equipment in the tenth embodimentof the invention constructed above will be hereinafter described. Whenan aperture diameter of ultrasonic beam is widened by the methoddescribed in the second embodiment, transducer elements not driven existbetween transducer elements driven. Therefore, a sound pressure islowered where the transducer elements not driven exist. In thisembodiment, in order to prevent the transducer elements not driven fromexisting when an aperture is widened, adjacent transducer elements areconnected by the high voltage switches. A transducer element which hasnot been driven in the second embodiment is driven at the same timing asof the adjacent transducer element to be driven. In result, lowering asound pressure is prevented.

Descriptions will be hereinafter given with the example of PA1 ofAperture K2 shown in FIG. 2. The transducer element 2-8 has not beendriven yet. Therefore, the high voltage switch 20-4 is turned ON, andthe transducer element 2-8 is also driven by high voltage transmissionpulse for driving the transducer element 2-7. The transducer elements2-10, 2-15, and 2-17 have not been driven yet as well. Therefore, thehigh voltage switches 20-5, 20-8, and 20-9 are turned ON, and thetransducer elements 2-10, 2-15, and 2-17 are also driven by high voltagetransmission pulse for driving the transducer elements 2-9, 2-16, and2-18.

As mentioned above, in the tenth embodiment of the invention, theultrasonic diagnostic device has a construction, wherein the highvoltage switches for connecting adjacent transducer elements are added.Therefore, lowering of a sound pressure can be prevented when anaperture is widened, a transmission circuit amount can be reduced, andan inexpensive ultrasonic diagnostic equipment can be realized whileperformance is maintained.

ELEVENTH EMBODIMENT

An eleventh embodiment of the invention is an ultrasonic diagnosticequipment, wherein diodes are inserted between transducer elements andhigh voltage switches.

FIG. 12 is a block diagram of a transmission/reception circuit of theultrasonic diagnostic equipment in the eleventh embodiment of theinvention. In FIG. 12, diodes 21-1 to 21-32 are. diodes for separatingreceiver signals for the transducer elements 2-1 to 2-32 from eachother. A general construction of the ultrasonic diagnostic equipment inthe eleventh embodiment is similar to of the ultrasonic diagnosticequipment in the tenth embodiment shown in FIG. 11, except that thediodes 21-1 to 21-32 are connected in series between the transducerelements and the high voltage switches.

Operation of the ultrasonic diagnostic equipment in the eleventhembodiment of the invention constructed above will be hereinafterdescribed. In the tenth embodiment, when the adjacent transducerelements are connected, there receiver signals become the same. In orderto prevent this, high voltage transmission pulse is applied to thetransducer elements through the diodes 21-1 to 21-32. In the case ofreceiver signals having a relatively small amplitude, the diodes 21-1 to21-32 are tuned OFF, and individuality of reception channels ismaintained. Therefore, deterioration of reception beam can be prevented.

As mentioned above, in the eleventh embodiment of the invention, theultrasonic diagnostic device has a construction, wherein the diodes areinserted between the transducer elements and the high voltage switches.Therefore, deterioration of reception beam can be prevented, atransmission circuit amount can be reduced, and an inexpensiveultrasonic diagnostic equipment can be realized while performance ismaintained.

Industrial Applicability

As evidenced by the foregoing descriptions, in the invention, highvoltage switches for selectively connecting ultrasonic transducerelements and transmission drive circuits of an ultrasonic diagnosticequipment, and low voltage switches for selecting ultrasonic transducerelements which receive ultrasonic echo are provided individually.Therefore, by respectively changing connection patterns of the highvoltage switches for transmission and connection patterns of the lowvoltage switches for reception, the following effects can be obtained.That is, even when the number of the transmission drive circuits isreduced, linear scanning can be performed without lowering precision,and an ultrasonic diagnostic equipment having a small circuit scale canbe realized at low cost.

1. An ultrasonic diagnostic equipment comprising; a probe having aplurality of arrayed ultrasonic transducer elements, a plurality oftransmission drive circuits for driving the ultrasonic transducerelements, a plurality of high voltage switches for connecting theultrasonic transducer elements and the transmission drive circuits, aplurality of limiters for clipping transmission pulse having a givenvoltage or more, which is generated at the transmission drive circuits,a cross point switch, which has input terminals whose number is largerthan of the transmission drive circuits, and performs sorting and addingsignals received at the ultrasonic transducer elements, low voltageswitches for connecting output signals of the limiters to the inputterminals of the cross point switch, A/D converters for convertingoutput signals of the cross point switch to digital signals, and a beamforming device for delay-adding the output signals of the A/Dconverters, wherein: an ultrasonic pulse transmission circuit has fewerchannels than a reception circuit.
 2. The ultrasonic diagnosticequipment according to claim 1, further comprising; a means for changingconnection patterns of the high voltage switches, and a means forturning ON/OFF the high voltage switches by a connection pattern withwhich an aperture wider than a minimum aperture determined by the numberof the transmission drive circuits is obtained.
 3. The ultrasonicdiagnostic equipment according to claim 2, further comprising; a meansfor identifying a type of a probe connected, and a means for changing asize of the aperture according to the type of the probe.
 4. Theultrasonic diagnostic equipment according to claim 2, furthercomprising; a means for inputting a displayed depth, and a means forchanging a size of the aperture according to the input displayed depth.5. The ultrasonic diagnostic equipment according to claim 2, furthercomprising; a means for inputting a display mode, and a means forchanging a size of the aperture according to the input display mode. 6.The ultrasonic diagnostic equipment according to claim 2, furthercomprising; a means for inputting a transmission focus depth, and ameans for changing a size of the aperture according to the inputtransmission focus depth.
 7. The ultrasonic diagnostic equipmentaccording to claim 2, further comprising; a means for inputting a centerfrequency of transmission pulse, and a means for changing a size of theaperture according to the input center frequency.
 8. The ultrasonicdiagnostic equipment according to claim 2, further comprising; a meansfor selecting whether a higher resolution is prioritized or whether awider dynamic range is prioritized, and a means for selecting transducerelements to be used according to characteristics to be prioritized. 9.The ultrasonic diagnostic equipment according to claim 1, wherein amemory for storing data for one sound ray, and an adder for adding anoutput of the memory and an output of the beam forming device areprovided on the output side of the beam forming device.
 10. Theultrasonic diagnostic equipment according to claim 2, further comprisinghigh voltage switches for connecting two adjacent transducer elements.11. The ultrasonic diagnostic equipment according to claim 10, furthercomprising diodes inserted between the high voltage switches and thetransducer elements.